RETICULARIA 149 



This species is by European authors reported from the United 

 States, but we have not seen it. Everything so-called received 

 here (Iowa) is L, minima. Morgan reports it from Ohio. 



B. RETICULARIE^E. 



Fructification sethalioid ; the sporangia generally poorly 

 defined, intricately associated, borne on a common hypothallus 

 and covered above by a common cortex, the lateral walls variously 

 perforate and incomplete, form a pseudo-capillitium ; spores 

 umber or ochraceous. 



Key to the Genera of the Reticularieae. 



A. Spores umber. 



a. Sporangia wholly indeterminate, their walls much consolidated 



below, fraying out above into long, slender threads, 



i . RETICULARIA 



b. Sporangia bounded, more or less distinctly, by broad perforate 



plates throughout 2. ENTERIDIUM 



B. Spores ochraceous . . . . . 3. DICTYDLETHALIUM 



i. Reticularia (Bull.) Rost. 



1791. Reticularia Bulliard, Champ, de la France, p. 95 (in part). 

 1873. Reticularia (Bulliard) Rost., Versuch, p. 6. 



Sporangia wholly indeterminate or undefined, their walls rep- 

 resented (?) by a spongy mass of so-called capillitium, consisting 

 of membranous plates, branching, anastomosing, vanishing 

 without order or symmetry, generally giving rise at the sides, 

 and especially above, to long slender flexuous threads ; outer 

 cortex silvery white ; hypothallus distinct white ; spore-mass 

 and threads umber or rusty brown. 



A single species, - 



i. RETICULARIA LYCOPERDON (Bulliard). 



PLATE X., Figs. 7, 7 a ; PLATE XII., Fig. 3; PLATE XVIII., Fig. 3. 

 1791. Reticularia lycoperdon Bulliard, Champ, de la France, p. 95. 



vEthalium pulvinate, 2-8 cm. broad, at first silvery white, 

 later less lustrous, the cortex irregularly and slowly deciduous ; 



